I loved the first level of System Shock, now that it's been modernized. Then I got to the second level, and resources were no longer scarce, and it didn't appear to be shaking up the formula from level to level, so now it feels like Doom with an inventory system rather than the games that took inspiration from System Shock.

Half-Life is still pretty great, but as far as organically teaching the player, it's far behind even its own sequel. There are a lot of cheap deaths that you just have to save scum your way through. My go-to example is that when Half-Life 1 introduces a sniper enemy, you see a hole in the wall that could look like a sniper's nest if I told you that they existed in the game and if you squint at it a little bit, so you just get shot in the back. In Half-Life 2, you emerge from Ravenholm, and a combine sniper with a laser sight is clearly trained on some escaping zombies, so that you know that snipers in sniper's nests are now a thing you'll have to contend with, and you get to observe it safely once before dealing with them in the game. That kind of thing. 90s PC games seemed to be worse at this than their successors and console games at the time.